There is no direct file which you can exchange or synchronize, but you have
api commands to read out the phonebook, which are more or less just text entries,
so its not that hard to post process that.
If its a one time thing it should be quite simple with some manual work.
If you expect to keep it synced, you would need some sync logic with some
checkup (like duplicates).
There are some 3rd party also offering phonebooks as a service,
so you do not need to have a TMS but they can manage them (either with
their TMS or some custom phonebook server.
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